The present invention relates to a pilot gas burner.
As is well known, devices of the above-mentioned type are used for controlling the lighting of gas burners such as those used, for example in ovens and boilers, as well as in decorative fireplaces.
Typically, a pilot burner, also known more briefly as a "pilot", has a duct which contains a nozzle and which has the task of determining the gas flow-rate, and a head mounted on the duct and carrying one or more flame jets for supplying gas to the main burner and to thermoelectric safety systems.
In pilot burners of this type, the nozzle is often mounted on the duct at the opposite end to the head, that is, it is accessible from below. This access is particularly inconvenient in pilot burners for decorative fireplaces because of they are generally in fairly inaccessible positions. There is therefore a need to have access to the gas-supply nozzle from above, that is, from the end of the duct bearing the head. To satisfy this need, in the prior art, a pilot burner has been proposed in which a counter-plate is fixed to the support plate by screws and the head of the burner is connected thereto. If the counter-plate is unscrewed, the head is released from the body of the duct, affording access to the nozzle. However, this solution is quite complex structurally and leads to some problems. In the first place, since gas-tightness between the nozzle and the duct is ensured by the tightening of the counter-plate onto the support plate, the slackening of the clamping screws of the counter-plate may cause anomalous gas leakages from the duct and between the duct and the nozzle. Moreover, since the nozzle is restrained in the duct in abutment with the head of the burner which in turn is clamped by means of the counter-plate, the removal of the head after the counter-plate has been unscrewed releases the nozzle which, owing to its small size can easily be lost.
The fixing of the counter-plate by means of screws is also quite inconvenient.